Replacing the septic system

We built our house thirty years ago and moved in during November. After thirty years, things start to go wrong and just before we went to Australia we wondered if there was something going wrong with the septic system so we had it emptied. After about a week in Sydney we got a message from our house sitter that the septic had backed up. After a Skype call, Bob organized that the tank be emptied and he also called a contractor to look at the situation. Since this looked like a major operation, we decided to wait until we returned from Oz to talk to the contractor about fixing the system.

The lid for our septic tank. This blog has a lot of photos that we will keep for documentation purposes so it is lengthy. However, you might find it interesting.

Driveway and side yard.

Mulch bin in the background.

Back of house.

The monster tractor / shovel arrives.

Will the monster fit between the trees?

Yes. Just fits down between the trees.

Smaller version for the delicate work.

Starting the exploratory dig to expose the tank.

Any grass we had has disappeared.

 

We headed out to vote and on our return the old tank had been removed and the new one installed. Since our house lies in the Critical Bay Area, we had to install a new special tank that has multiple chambers and a built in aeration system. The lids are plastic.

Pipe from our house to the septic.

One of the chambers has a pump that needs electricity to operate. A trench was dug from our electrical service to the tank.

The control box next to our electric service.

Filling in the trench. These two young blokes work for the contractor. One of them is the contractor's son.

The cost of the new tank and its installation was about $11,000. Fortunately, the state has a special fund that pays all of this. Your tax dollars at work.

The problem was not in our old septic tank but in our drain field so it needed to be found. We have old photos from when the house was built thirty years ago but only one of the drain field that did not really show the location.

The old trench. Thirty years ago, standards were much lower.

The bloke from the county who supervises all septic installations. He had a new young employee who he was training. We had to wait a month to get the work done because most of the trained inspectors resigned to get higher paying jobs in nearby counties. 

Incidentally, we did very well in restricting our usage of water and did not have to have the tank pumped out again until it was removed. Our exchange family and house sitters also restricted their use which was very helpful. It costs over $200 to have the tank emptied.

Finding the remains of squashed pipe.

We were hoping that since the sandy soil and stone was looking dry that perhaps we would not have to have a new drain field but when they dug down, they found damp ground that was black. We would need a new field.

The perk test was carried out which determines how well water seeps into the ground. The water seeped very quickly but the inspector was thorough and wanted a deeper hole to be dug to see what lay below and they found some clay about 24' feet down. Standards are much tougher now than they were thirty years ago.

We all agreed on a new location between the house and the old drain field. We could not go further away from the house because it is close to our back property line.

The initial specifications of 4' wide, 18' deep and 40' long. The depth seemed horrendously deep but the inspector said that since the new trench was higher up the hill, it might be possible to have a less deep trench if no clay was found in the new location. Note that he specified 14' of stone which is expensive.

Next day, work started on the new trench.

Marking out the 40' length.

A truck load of stones to go into the trench.

A deep hole was dug again to see what was going on way down and eventually clay was found. However the quality of the soil and sand was enough to convince the inspector that a less deep trench would be ok, particularly as the design of the septic tank results in very clean water going into the septic field.

Six feet is a lot less than sixteen feet, particularly when most of the trench has to be filled with stone.

Measuring the depth.

Pipes to be installed.

Digging the new 6' feet deep trench.

Laying new pipe.

We would actually finish up with two drain fields. The old one would have a chance to dry out while the new one was used. After two years we could turn a knob and start using the old field again allowing the new field to dry out.

The water in drain fields attracts roots from nearby trees and these roots can eventually block the pipes. 

Outlet connection to the tank.

The new trench, six feet deep.

The first truck load of stones is tipped in. 

The young blokes raked the stone into a level surface in the trench.

It's a big truck.

The contractor who is a really nice guy. The inspector said he really liked working with him and he knew his stuff. While Dennis was operating the big shovel, the inspector mentioned to me that he sees a lot of operators and about 15% of them should not be allowed near the controls, 75% are generally ok and there are 10% who are really artists with the bucket. Dennis belongs to the last group.

The wheels on the truck started spinning when Dennis tried to drive up the hill so eventually they hooked up the smaller tractor to help. It did not work and the truck was stuck.

So the big monster was brought into action.

That worked. Nothing stops that beast.

More stone going into the trench.

They discovered that one of the brakes on the back wheels was sticking which was causing the problem.

One load was not enough to fill the trench so Dennis went off for another load. This time there was enough and actually some left over. Two loads of stone costs a lot less than six or more and we will have to pay for this.

The knob that directs the outflow from the tank to whichever field is selected.

The pipe lying on top of the stones.

The final lot of stones going into the trench.

You would develop muscles pushing the stone around.

Black porous wrap.

Pipe to the knob that selects the drain field to be used.

Notice the little holes on the side of the pipe.

A bit more stone laid on top of the pipe.

Covering the pipe and stone with the porous black wrap. The next step is to fill the trench with dirt and sand and the wrap keeps the sand and dirt separated from the stones.

The trench was filled and they then smoothed out everything.

All that is visible of the pipe that controls the direction of flow to either trench.

Looking over to our lot next door.

It is too late in the season to plant grass which will have to wait until spring next year. We had to have two poplar trees removed to allow the monster to maneuver but it has opened things up. With all the shade we have trouble getting grass to grow but with the extra sun resulting from the loss of the two trees, perhaps we will do better with grass this time.

Before the work was done, Marianne dug up some daffodil bulbs and we will re-plant them shortly while the ground is freshly dug. In the meantime, we expect all the bare dirt to be covered by the leaves that will fall off the trees in the next week or so. All the leaves you see on the trees will be fallen.

So an interesting experience. At least we can flush the toilet and run the dishwasher and wshing machine whenever we want.